ParcelableHolder shouldn't write anything for empty case

If neither Parcel nor Parcelable exists, ParcelableHolder'd better
write nothing like NDK and C++ backend.

In the case of empty ParcelableHolder
As-is(Java):
 4 -> Size
 -1 -> Existence(empty string)

To-be(NDK, C++ now):
 0 -> Size

Test: atest CtsNdkBinderTestCases
Bug: 173682663
Change-Id: I816108fdc59170ea7408f0633295ba978f1ef9d5